The disclosed embodiments generally pertain to gas turbine engines. More particularly present embodiments relate to the structure of composite woven fan outlet guide vanes and optionally including a hollow airfoil.
In a gas turbine engine, air is pressurized in a compressor and mixed with fuel in a combustor for generating hot combustion gases which flow downstream through turbine stages. A typical gas turbine engine generally possesses a forward end and an aft end with its several core or propulsion components positioned axially therebetween. An air inlet or intake is located at a forward end of the engine. Moving toward the aft end, in order, the intake is followed by a fan, a compressor, a combustion chamber, and a turbine. It will be readily apparent from those skilled in the art that additional components may also be included in the engine, such as, for example, low-pressure and high-pressure compressors, and low-pressure and high-pressure turbines. This, however, is not an exhaustive list.
The compressor and turbine generally include rows of airfoils that are stacked axially in stages. Each stage includes a row of circumferentially spaced stator and a rotor assembly which rotates about a center shaft or axis of the turbine engine. A multi-stage low pressure turbine follows the multi-stage high pressure turbine and is typically joined by a second shaft to a fan disposed upstream from the compressor in a typical turbo fan aircraft engine configuration for powering an aircraft in flight. These turbine stages extract energy from the combustion gases.
The stator is formed by a plurality of nozzle segments which are abutted at circumferential ends to form a complete ring about the axis of the gas turbine engine. Each nozzle segment may comprise one or more vanes which extend between an inner band and an outer band. The stator nozzles direct the hot combustion gas in a manner to maximize extraction at the adjacent downstream turbine blades.
Turbine rotor assemblies typically include at least one row of circumferentially-spaced rotor blades. Each rotor blade includes an airfoil that having a pressure side and a suction side connected together at leading and trailing edges. Each airfoil extends radially outward from a rotor blade platform. Each rotor blade may also include a dovetail that extends radially inward from a shank extending between the platform and the dovetail. The dovetail is used to mount the rotor blade within the rotor assembly to a rotor disc or spool. Known blades are hollow such that an internal cooling cavity is defined at least partially by the airfoil, platform, shank, and dovetail.
In operation, air is pressurized in a compressor and mixed with fuel in a combustor for generating hot combustion gases which flow downstream through the multiple turbine stages. Typical gas turbine engines utilize a high pressure turbine and low pressure turbine to maximize extraction of energy from high temperature combustion gas. In the high pressure turbine, combustion gas engages the stator nozzle assembly, which directs the combustion gases downstream through the row of high pressure turbine rotor blades extending radially outwardly from a supporting rotor disc. A high pressure turbine first receives the hot combustion gases from the combustor. The high pressure turbine includes a first stage nozzle and a rotor assembly having a disk and a plurality of turbine blades. An internal shaft passes through the turbine and is axially disposed along a center longitudinal axis of the engine. Blades are circumferentially distributed on a rotor and extend radially causing rotation of the internal shaft. The internal shaft is connected to the rotor and the air compressor, such that the turbine provides a rotational input to the air compressor to drive the compressor blades. This powers the compressor during operation and subsequently drives the turbine. As the combustion gas flows downstream through the turbine stages, energy is extracted therefrom and the pressure of the combustion gas is reduced.
In the area of the fan and by-pass duct of the gas turbine engine, a fan frame assembly is disposed having a plurality of guide vanes. These vanes are typically formed of metal and are used to turn air exiting the fan within the by-pass duct. However, as with most concerns involving gas turbine engines, including aviation uses, it is desirable to reduce the weight of the engine as one manner in improving fuel efficiency and engine performance.
The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention is to be bound.